Apparatus and method of exposing light to a semiconductor device having a curved surface

ABSTRACT

A semiconductor manufacturing station ( 50 ) exposes light on a surface area of a spherical semiconductor device or ball ( 52 ). A mask pattern generator ( 56 ) provides a pattern of light, which undergoes temporal changes to collectively represent an image. The mask pattern generator has an active exposure contour ( 80 ) that provides a portion of the overall image. The pattern of light is directed though a lens ( 62 ) to the surface area of the semiconductor device. The semiconductor device rotates in relation to the temporal changes in the pattern of light to expose the pattern of light over a portion of a surface area of the semiconductor device. The exposure contour has a narrower center and becomes wider moving away from the center. The exposure contour may have a curvature.

FIELD OF THE INVENTION

The present invention relates, in general, to semiconductormanufacturing equipment and processes and, more particularly, to anapparatus and method of exposing a light source to a semiconductordevice having a curved surface.

BACKGROUND OF THE INVENTION

Semiconductor devices are commonly used in many types of electronicproducts. The manufacturing of a semiconductor device typically involvesgrowing a cylindrical-shaped silicon (or other base semiconductivematerial) ingot. The ingot is sliced into circular flat wafers. Througha number of thermal, chemical, and physical processes, includingdiffusion, oxidation, epitaxial growth, ion implantation, deposition,etching, sputtering, polishing, and cleaning active semiconductorsputtering, surfaces of the wafer. The wafer is cut into individualrectangular semiconductor die which are then mounted and attached to aleadframe, encapsulated, and packaged as discrete or integratedcircuits. The packaged discrete and integrated circuits are mounted to aprinted circuit board and interconnected to perform the desiredelectrical function.

Another type of semiconductor device, known as a spherical-shapedsemiconductor device or ball, has emerged in the industry to offer anumber of advantages over flat semiconductor wafers and rectangularsemiconductor die. The manufacture of the semiconductor ball isdisclosed in U.S. Pat. No. 5,955,776. The semiconductor ball ismanufactured using less complex and less expensive equipment as comparedto wafer-type semiconductor manufacturing. The physical characteristicsof the semiconductor ball provides for easy transport through pipes andtubes filled with a gaseous or fluid medium, which reduces the need forexpensive, large scale, open clean rooms. The enclosed transport reducesthe potential for exposure to contaminants, which reduces defects andincreases the production yield.

A typical semiconductor ball has a diameter of 1.0 millimeters (mm) orless and may contain active semiconductor devices and passive devicesover virtually its entire surface area. The spherical shape increasesboth the useable area of the semiconductor device and the deviceintegration density for a given footprint. The semiconductor ball mayinterconnect to a printed circuit board, or to other semiconductorballs, at any location on its surface thereby reducing, simplifying, andadding flexibility to the interconnect layout. The flexible interconnectallows for three dimensional clustering of the semiconductor balls eachhaving multiple active layers and multiple metal layers in anydirection. The spherical shape of the semiconductor ball providesstructural strength and integrity such that conventional assembly andpackaging become unnecessary in some applications.

The semiconductor ball undergoes a variety of conventional thermal,chemical, and physical processing steps during manufacture. Several ofthe processing steps involve exposure of the semiconductor ball to alight source. For example, an etching process to selectively removesemiconductor material involves application of a photoresist material toa surface area. A mask is positioned above the surface area and exposedto a light source. The pattern in the mask either blocks the light orallows it to pass to the semiconductor surface area. Accordingly,portions of the surface area of the semiconductor ball are exposed tothe light according to the mask pattern. The photoresist on thoseportions of the surface area that are exposed to light is polymerized.The photoresist on those portions of the surface area that are notexposed to light is not polymerized. The mask is removed and thephotoresist is developed to remove the non-polymerized photoresist. Asolution of nitric and hydrofluoric (HF) acid is applied the surfacearea to etch away the material which had been under the non-polymerizedphotoresist. The polymerized photoresist and the underlying materialremain. The photoresist etch process may also be configured to operatein the opposite mode.

For conventional semiconductor wafers, the light exposure incident toits flat surface is relatively uniform and even. On the other hand, theexposure of light to a curved surface such as found on a sphericalsemiconductor ball presents a number of challenges to the manufacturingprocess. In general, it is impractical to cover the entire surface ofthe semiconductor ball with one mask pattern. Moreover, it is difficultto focus the light uniformly over a significant portion of the curvedsurface of a spherical body. If the focus of the light source isdirected to one focal point on the curved surface, then the rest of thepattern image diminishes, blurs, or distorts on the curved surfacemoving away from the focal point. The exposure of light to a curvedsurface results in a non-uniform distribution of the light andnon-uniform focus and clarity of the projected image radially from thefocal point. In addition, the light incident to the focal point on thecurved surface normal to the direction of the light path will have astronger intensity than a second point on the curved surface somedistance from the focal point. The light striking the second point willhave an angle of incidence less than 90° and consequently a lowerintensity. In the etching process, the photoresist on the surface areaexposed to a lower intensity light will develop at a different rate thanthe photoresist on the surface area exposed to a higher intensity light.

For example, as shown in prior art FIG. 1, a light from light source 10is incident to mask 12. Mask 12 projects a pattern or image by thetransmitted and non-transmitted portions of the light through mask 12,which is then focused by lens 14 to a focal point 16 on the surface ofsemiconductor ball 18. The spherical shape of semiconductor ball 18causes the pattern to blur or distort and become larger in the radialdirection from focal point 16. Circle 20 represents the surface area ofsemiconductor ball 18, centered about focal point 16, where the maskpattern image is relatively sharp and clear without appreciabledistortion or degradation. Area 22 represents the portion of the surfacearea of semiconductor ball 18 where the mask pattern image isappreciably distorted or degraded, given that the light is focused atfocal point 16.

Assume a distance r1 from focal point 16 to the outer perimeter ofcircle 20 and a distance r2 from focal point 16 to the edge of the planedefined by lines 24. The distance d1 represents the difference betweenthe light path from lens 14 to focal point 16 and the light path fromlens 14 to a point at r1. The distance d2 represents the differencebetween the light path from lens 14 to focal point 16 and the light pathfrom lens 14 to a point at r2. The ratio d2:d1 becomes large as theratio r2:r1 increases due to the curvature of the surface ofsemiconductor ball 18. The distortion of the light exposure for surfaceareas of semiconductor ball 18 less than distance d1 is consideredwithin acceptable limits. The distortion of light exposure for surfacearea of semiconductor ball 18 greater than distance d1, i.e. area 22, isoutside the acceptable limits.

The distortion of light exposure within area 22 of FIG. 1 reduces theaccuracy of the mask pattern image and could result in defects in thedevices formed on semiconductor ball 18 in that area. The lack ofresolution in the light exposure also makes it difficult to design highquality, high density circuits over continuous areas with the requisiteprecision in focal quality of the light exposure. As the integrationdensity increases and the mask patterns become more elaborate, it isdifficult to form minute circuits on the curved surface of semiconductorball 18 near the edges of circle 20. Another problem is found in formingcontinuous circuits such as integrated inductors and coils. The jointsbetween adjacent exposable circles like 20 do not match well whichincreases the resistance at the joints and degrades the intendedfunction.

One solution is to reduce the pattern size relative to the surface areaof semiconductor ball 18 and thereby reduce the distortion effects.Semiconductor ball 18 is divided into a number of plane surfaces, eachwith a center focal point. Line 24 in FIG. 1 defines one such planecentered at focal point 16. Each plane surface is made small enough toprovide a distortion-free mask pattern image, or at least one withacceptable distortion, over the majority of its surface area. However,such a solution requires more total exposures to cover the requiredsurface area and possible re-alignment of semiconductor ball 18 for eachexposure, adding the manufacturing processing time.

A need exists for an optical exposure system that allows light to beuniformly exposed across the surface area of a curved object.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a semiconductor light exposure system as found in the priorart;

FIG. 2 is a semiconductor manufacturing system for exposing light on thesemiconductor ball;

FIG. 3 illustrates further detail of the semiconductor manufacturingsystem of FIG. 2;

FIGS. 4 a-4 b illustrate exposures of multiple surface areas of thesemiconductor ball;

FIGS. 5 a-5 b illustrate options for various shapes of the activeexposure contour on the semiconductor ball;

FIGS. 6 a-6 b illustrate further detail of the active exposure contourson the semiconductor ball; and

FIG. 7 is an alternate embodiment of the semiconductor manufacturingsystem.

DETAILED DESCRIPTION OF THE DRAWINGS

A semiconductor manufacturing system or station 50 is shown in FIG. 2for exposing light on a spherical semiconductor device or ball 52, orother spherical shaped object, or object having a curved surface.Semiconductor ball 52 may contain active semiconductor devices, such astransistors and diodes, and passive devices, such as resistors andcapacitors, over any part or substantially all of its surface area. Themanufacture of semiconductor ball 52 is disclosed in U.S. Pat. No.5,955,776 and incorporated herein by reference. Semiconductor ball 52has the ability to interconnect to a printed circuit board, or to othersemiconductor balls, at virtually any location on its surface, whichreduces and simplifies the interconnect layout. The flexibleinterconnect allows for three dimensional clustering of thesemiconductor balls each having multiple active layers and multiplemetal layers in any direction. The spherical shape of semiconductor ball52 provides a structural strength and integrity such that conventionalassembly and packaging become unnecessary in some applications.

Semiconductor ball 52 undergoes a variety of thermal, chemical, andphysical processes, including diffusion, oxidation, epitaxial growth,ion implantation, deposition, etching, sputtering, polishing, andcleaning, during manufacturing to form the active semiconductor devicesand passive devices on its surface. Several of the manufacturing processsteps involve exposure of semiconductor ball 52 to a light source. Onesuch manufacturing step is an etching process wherein a photoresistlayer is applied to a portion of the surface of semiconductor ball 52.Certain areas of the photoresist layer are exposed to a light source,while other areas of the photoresist layer are not exposed to the lightsource, as determined by a mask filter. The photoresist material that isexposed to the light source is polymerized. After developing thephotoresist material to remove the non-polymerized photoresist, asolution of nitric and HF acid is applied to remove the material whichhad been underlying the non-polymerized photoresist. The polymerizedphotoresist and underlying material remain.

Semiconductor manufacturing station 50 representssemiconductor-manufacturing equipment capable of emitting light onsemiconductor ball 52 for the above-described manufacturing process andother semiconductor manufacturing steps requiring an exposure to a lightsource. A light source 54 generates a light from a high-pressure mercurylamp. The light from light source 54 is incident to mask patterngenerator 56. Computer 58 stores the desired mask pattern or image thatis to be exposed on semiconductor ball 52. The mask pattern definesthose areas on the surface of semiconductor ball 52 which are to beexposed to light and those areas, which are not to be exposed to light.The mask pattern can have many sizes, shapes, patterns, and detailsdepending on the desired devices to be formed and disposed on thesurface of semiconductor ball 52.

Mask pattern controller 60 receives commands from computer 58 accordingto the desired mask pattern. Mask pattern generator 56, which can beimplemented as a digital mirror device (DMD), receives control signalsfrom computer 58 to program the mask pattern. Further description ofmask pattern generator 56 is disclosed in U.S. Pat. No. 6,251,550 andincorporated herein by reference. In the present example, mask patterngenerator 56 includes a matrix of 600×600 individually controlledmirrors, each approximately 10 mm×10 mm. Mask pattern controller 60converts to the desired mask pattern received from computer 58 to aseries of control signals sent to each mirror of mask pattern generator56 to individually program its angle and orientation. Thus, certainmirrors of mask pattern generator 56 are tilted to transmit light tolens 62 for those areas, which are intended to be exposed to lightaccording to the mask pattern. The light image from mask patterngenerator 56 passes through lens 62, which focuses the light image onthe surface of semiconductor ball 52 centered at focal point 66. In analternate embodiment, a transmission-type liquid crystal display may beused to emit or transmit light according to the desired mask pattern.

Computer 58 is capable of storing multiple mask patterns. Mask patterncontroller 60 can readily re-configure mask pattern generator 56according to the desired mask pattern.

Semiconductor ball 52 is attached to shaft or armature 68 by a suctioncup or other attachment mechanism. Shaft 68 is connected to rotationalmotor 72. Computer 58 provides control signals to rotational motor 72that generates rotational torque along shaft 68 to spin semiconductorball 52 in either direction on axis X. As semiconductor ball 52 rotateson its axis X, the light has a continuous focal exposure completelyaround the circumference of the sphere defined by line 74.

Turning to FIG. 3, further detail of mask pattern generator 56 is shownwith exposure contour 80 defining the active surface area of the maskpattern generator. Elements having the same reference number as used inFIG. 2 have a similar function. Exposure contour 80 can be one mirror ortransmitting pixel in width, or many mirrors or pixels in width. Eachmirror is about 17.0 microns square. In the present example, exposurecontour 80 has length L₈₀=10.0 mm and width W₈₀=2.0 mm. Exposure contour80 is projected through lens 62 onto the surface of semiconductor ball52 as exposure contour 82 having length L₈₂.

Computer 58 configures mask pattern controller 60 with a portion of theoverall mask pattern image corresponding to exposure contour 80. Themask pattern images include patterns of the desired devices to be formedand disposed on the surface of semiconductor ball 52. Assume the overallmask pattern image is a rectangular area having a length L₈₀ and a widthmuch greater than W₈₀. Computer 58 configures mask pattern controller 60to scroll the overall mask pattern image across exposure contour 80. Inanother perspective, exposure contour 80 scans across the mask patternimage.

At time t1, a first mirror or pixel row of length L₈₀ of exposurecontour 80 is programmed with a first row of the mask pattern image. Asecond mirror or pixel row of length L₈₀ of exposure contour 80 isprogrammed with a second row of the mask pattern image, and a thirdmirror or pixel row of length L₈₀ of exposure contour 80 is programmedwith a third row of the mask pattern image. The first, second, and thirdmirror or pixel rows of exposure contour 80 are projected through lens62 onto the surface of semiconductor ball 52. At time t2, the thirdmirror or pixel row of exposure contour 80 is programmed with a fourthrow of the mask pattern image. The third row of the mask patterngenerator is shifted to the second mirror or pixel row of exposurecontour 80, and the second row of the mask pattern generator is shiftedto the first mirror or pixel row of exposure contour 80. The first,second, and third mirror or pixel rows of exposure contour 80 areprojected through lens 62 onto the surface of semiconductor ball 52. Attime t3, the third mirror or pixel row of exposure contour 80 isprogrammed with a fifth row of the mask pattern image. The fourth row ofthe mask pattern generator is shifted to the second mirror or pixel rowof exposure contour 80, and the third row of the mask pattern generatoris shifted to the first mirror or pixel row of exposure contour 80. Thefirst, second, and third mirror or pixel rows of exposure contour 80 areprojected through lens 62 onto the surface of semiconductor ball 52. Theprocess continues across the mask pattern image as it undergoes temporalchanges while scrolling across exposure contour 80 to collectivelyrepresent an image.

Computer 58 synchronizes the rotation of shaft 68 and semiconductor ball52 in relation to, and to coincide with, the shifting mask pattern ofexposure contour 80 projected as exposure contour 82 on the sphere. Themask pattern image is projected onto the moving surface of semiconductorball 52 and plays as a continuous real-time video projection of the maskpattern on the surface of the sphere. The length of exposure contour 80and focal properties of lens 62 are selected such that the length L₈₂ ofexposure contour 82 provides a sharp and clear continuous projection ofthe mask pattern on the curved surface of semiconductor ball 52 withoutany appreciable distortion or degradation of the image, or at leastacceptable distortion depending on the application, on the curvedsurface. A mask pattern image can be projected around the entirecircumference of semiconductor ball 52, shown as surface area 84, tocircumscribe the sphere without realignment and without any appreciabledistortion or degradation of the image over the designated curvedsurface. The extended projection area is beneficial when forming longdevices such as inductors.

The length L₈₂ depends in part on the required resolution and allowabledistortion in the mask pattern. The mask pattern can be arranged so thathigh precision devices are located near the center of exposure contour82 and low precision devices are positioned nearer the outer boundary ofsurface area 84.

To cover other surface areas, semiconductor ball 52 is rotated withrespect to shaft 68 and the projection process is repeated. For example,as shown in FIG. 4 a, surface area 84 is exposed around thecircumference of semiconductor ball 52 during a first exposure.Semiconductor ball 52 is rotated 90 degrees with respect to shaft 68 andrealigned. The projection process is repeated to expose surface area 86although a portion of the mask pattern is blanked so as to not overlapexposed area 84. FIG. 4 b shows the same concept with fournon-overlapping exposure areas 90, 91, 92, and 93. For each exposurearea, semiconductor ball 52 is rotated 45 degrees and realigned for theexposure process. The narrower the exposure area, the higher resolutionthe mask pattern and higher precision devices that can be formed.However, more exposure areas involved more manufacturing steps tocompletely cover the semiconductor ball.

One advantage of the continuous shifting projection of the mask patternis that if a mirror or pixel of mask pattern generator 56 is defective,the adjacent mirrors or pixels in the same column of exposure contour 80will cover or help fill in the missing portions of the pattern as therespective row of the mask pattern image shifts to the adjacent row ofexposure contour 80.

Another advantage of the exposure process described herein is related tothe intensity of the light incident to the surface of semiconductor ball52. As described in the Background of the Invention, for a curvedsurface, the light intensity decreases, as the angle of incident becomesless than 90 degrees. In the etching process, the photoresist willpolymerize at a rate determined by the intensity of the light exposure.Thus, a uniform intensity exposure is desirable.

By rotating semiconductor ball 52 under the light source, the lightintensity is uniform at least around the circumference of the sphere foreach relative distance from centerline 94 of exposure area 96 shown inFIG. 5 a. However, due to the spherical shape of semiconductor ball 52,there is still some difference in light intensity incident to thesurface moving across exposure area 96. The light intensity decreases asit moves away from centerline 94. To compensate for the decrease inlight intensity moving away from centerline 94, exposure contour 97 ismade progressively wider moving toward its edge as shown in FIG. 5 a.The additional width of exposure contour 97 moving away from centerline94 provides a longer exposure time for those areas receiving a lowerlight intensity. The varying width of exposure contour 97 is determinedby integrating the decrease in light intensity. The closer to the edgeof exposure contour 97 and the lower the light intensity, the longerexposure time. The net effect is a substantially uniform light intensityacross the width of exposure area 96 and around the circumference of thesphere.

Another problem noted in the Background of the Invention is the tendencyof the image to blur and become distorted moving away from centerline 94as shown in FIG. 5 b. To compensate for the distortion, the exposurecontour 97 is curved across exposure area 98 in opposition to thecurvature of the surface of semiconductor ball 52 as shown in FIG. 5 b.By this compensation, the entire length of the exposure contour has thesame focal point.

Further detail of exposure contour 97 is shown in FIGS. 6 a and 6 b. Theshape of exposure contour 97 is selected such that all positions alongline of focus 95 have the same quantity of light 99.

An alternate embodiment of the semiconductor manufacturing station isshown in FIG. 7. Semiconductor manufacturing station 100 includes alight source 102 for generating a light. The light from light source 102is focused by lens 106 and projected onto mask pattern generator 108.Computer 110 stores the desired mask pattern or image that is to beexposed on semiconductor ball 112. Mask pattern generator 108 receivescontrol signals on conductors 114 from computer 110 to program the maskpattern. The active area of mask pattern generator 108 is an exposurecontour (not shown) similar to exposure contour 80 in FIG. 3. The lightimage from mask pattern generator 108 is reflected by mirror 118 andpasses through stop ring 120. Stop ring 120 is a diaphragm forcontrolling focal depth. Lens 122 then focuses the light image onexposure contour 124 on the surface of semiconductor ball 112.

Semiconductor ball 112 is attached to shaft or armature 126 by a suctioncup or other attachment mechanism. Shaft 126 is connected to rotationalmotor 128. Computer 110 provides control signals to rotational motor 128that generates rotational torque along shaft 126 to spin semiconductorball 112 in either direction on axis X. As semiconductor ball 112rotates on its axis X, the light has a continuous focal exposurecompletely around the circumference of the sphere defined by lines 130.

Computer 110 controls mask pattern generator 108 to scroll the overallmask pattern across the active exposure contour area as described above.The mask pattern is projected on exposure contour 124 of the surface ofsemiconductor ball 112. The mask pattern generator provides a pattern oflight, which undergoes temporal changes to collectively represent animage. Computer 110 synchronizes the rotation of shaft 126 andsemiconductor ball 112 in relation to, and to coincide with, theshifting mask pattern projected as exposure contour 124 on the sphere.The mask pattern image is projected onto the moving surface ofsemiconductor ball 112 which plays as a continuous real-time videoprojection of the mask pattern on the surface of the sphere. The lengthof the active exposure contour of mask pattern generator 108 and focalproperties of lens 122 are selected such that the length L₁₂₄ ofexposure contour 124 provides a sharp and clear continuous projection ofthe mask pattern on the curved surface of semiconductor ball 112 withoutany appreciable distortion or degradation of the image on the curvedsurface. A mask pattern image can be projected around the entirecircumference of semiconductor ball 112, shown as surface area 132,without realignment of the sphere and without any appreciable distortionor degradation of the image over entire curved surface.

The mask pattern image across exposure contour 124 is also reflectedback through lens 122, stop ring 120, mirror 118, and lens 140 toimaging receiver 138, also known as a charge coupled device (CCD).Imaging receiver 138 converts the reflect image of exposure contour 124to electrical signals. The electrical signals are sent to imagingmonitor 140 for display and further to computer 110 for processing.Imaging receiver 138 and imaging monitor 140 are utilized in analignment process as described in copending U.S. patent applicationentitled “System and Method for Detecting and Position Deviations of anObject having a Curved Surface”, Attorney Docket No. 981009.90031.

In summary, a semiconductor manufacturing station exposes light on asurface area of a spherical semiconductor device. A mask patterngenerator provides a pattern of light, which undergoes temporal changesto collectively represent an image. The mask pattern generator has anactive exposure contour, which provides a portion of the overall image.The pattern of light is directed though a lens to the surface area ofthe semiconductor device. The semiconductor device rotates in relationto the temporal changes in the pattern of light to expose the pattern oflight over a portion of a surface area of the semiconductor device. Acomputer synchronizes the rotation of the shaft and the semiconductordevice in relation to, and to coincide with, the shifting mask patternof the active exposure contour projected on the sphere. A mask patternimage can be projected around the entire circumference of thesemiconductor device to circumscribe the sphere without realignment andwithout any appreciable distortion or degradation of the image overentire curved surface.

Although the present invention has been described with respect topreferred embodiments, any person skilled in the art will recognize thatchanges may be that changes be made in form and detail, and equivalentsmay be substituted for elements of the invention without departing fromthe spirit and scope of the invention. Many modifications may be made toadapt to a particular situation or material to the teaching of theinvention without departing from the essential scope of the invention.Therefore, it is intended that the invention not be limited to theparticular embodiments disclosed for carrying out this invention, butthat the invention will include all embodiments falling within the scopeof the appended claims.

1. An optical apparatus for exposing light on a surface area of anobject having a curvature, comprising: a mask for providing a pattern oflight which undergoes temporal changes to collectively represent animage; a lens positioned to focus the pattern of light on the object;and a motor having a shaft coupled to the object for rotating the objectin relation to the temporal changes in the pattern of light to exposethe pattern of light over a portion of the surface area of the object.2. The optical apparatus of claim 1, wherein the object is a sphericalobject.
 3. The optical apparatus of claim 2, wherein the sphericalobject is a semiconductor device.
 4. The optical apparatus of claim 1,wherein a first exposed portion of the surface area of the object has awidth and circumscribes the object.
 5. The optical apparatus of claim 4,wherein a second exposed portion of the surface area of the object has awidth and is non-overlapping with respect to the first exposed portionof the surface area of the object.
 6. The optical apparatus of claim 1,wherein the mask includes an exposure contour for providing the patternof light.
 7. The optical apparatus of claim 6, wherein the exposurecontour has a width at a center and becomes wider moving away from thecenter to an edge of the exposure contour so as to expose the edge ofthe exposure contour for a longer period of time than the center of theexposure contour.
 8. The optical apparatus of claim 6, wherein theexposure contour has a curvature.
 9. The optical apparatus of claim 1,wherein the mask includes a mask pattern generator having an activeexposure contour for providing the pattern of light.
 10. The opticalapparatus of claim 9, wherein the mask pattern generator comprises adigital mirror device.
 11. The optical apparatus of claim 9, wherein themask further includes a mask pattern controller operating in response tocontrol signals and providing a portion of a mask pattern to the activeexposure contour of the mask pattern generator.
 12. A method of exposinglight on a surface area of an object having a curvature, comprising:providing a pattern of light through a mask which undergoes temporalchanges to collectively represent an image; directing the pattern oflight to the surface area of the object; and rotating the object inrelation to the temporal changes in the pattern of light to expose thepattern of light over a portion of the surface area of the object. 13.The method of claim 12, wherein the object is a spherical semiconductordevice.
 14. The method of claim 12, further including the step ofproviding a first exposed portion of the surface area of the objecthaving a width and circumscribing the object.
 15. The method of claim14, further including the step of providing a second exposed portion ofthe surface area of the object having a width and non-overlapping withrespect to the first exposed portion of the surface area of the object.16. The method of claim 12, wherein the mask includes an exposurecontour for providing the pattern of light.
 17. The method of claim 16,wherein the exposure contour has a width at a center and becomes widermoving away from the center to an edge of the exposure contour so as toexpose the edge of the exposure contour for a longer period of time thanthe center of the exposure contour.
 18. The method of claim 16, whereinthe exposure contour has a curvature.
 19. The method of claim 12,wherein the mask includes a mask pattern generator having an activeexposure contour for providing the pattern of light.
 20. The method ofclaim 19, wherein the mask pattern generator comprises a digital mirrordevice.
 21. A method of manufacturing a semiconductor device having acurved surface area, comprising: providing a pattern of light through amask which undergoes temporal changes to collectively represent animage; directing the pattern of light to the curved surface area of thesemiconductor device; and rotating the semiconductor device in relationto the temporal changes in the pattern of light to expose the pattern oflight over a portion of the curved surface area of the semiconductordevice.
 22. The method of claim 21, wherein the semiconductor device isa spherical semiconductor device.
 23. The method of claim 22, furtherincluding the step of providing a first exposed portion of the curvedsurface area of the semiconductor device having a width andcircumscribing the semiconductor device.
 24. The method of claim 23,further including the step of providing a second exposed portion of thecurved surface area of the semiconductor device having a width andnon-overlapping with respect to the first exposed portion of the surfacearea of the semiconductor device.
 25. The method of claim 21, whereinthe mask includes an exposure contour for providing the pattern oflight.
 26. The method of claim 25, wherein the exposure contour has awidth at a center and becomes wider moving away from the center to anedge of the exposure contour so as to expose the edge of the exposurecontour for a longer period of time than the center of the exposurecontour.
 27. The method of claim 25, wherein a length of the exposurecontour has a curvature.
 28. A method of exposing light on asemiconductor device having a curved surface area, comprising:generating a pattern of light; directing the pattern of light to thecurved surface area of the semiconductor device; and rotating thesemiconductor device to expose the pattern of light over a portion ofthe curved surface area of the semiconductor device.
 29. The method ofclaim 28, wherein the semiconductor device is a spherical semiconductordevice.
 30. The method of claim 28, wherein a first exposed portion ofthe curved surface area of the semiconductor device has a width andcircumscribes the semiconductor device.
 31. The method of claim 30,wherein a second exposed portion of the curved surface area of thesemiconductor device has a width and is non-overlapping with respect tothe first exposed portion of the curved surface area of thesemiconductor device.
 32. The method of claim 28, wherein the pattern oflight is generated through a mask having an exposure contour.
 33. Themethod of claim 32, wherein the exposure contour has a width at centerand becomes wider moving away from the center.
 34. The method of claim32, wherein the exposure contour has a curvature.